Seal tester for pressurized containers



R. A. NEISS SEAL TESTER FOR PRESSURIZED CONTAINERS Dec. 8, 1959 2 Sheets-Sheet 1 Filed Aug. 27, 195'! 4 2 a l 7 3 I J! a l I Z Z 8: 5 J! ..ll 5 M m l 5 r M 2 \lilllilll. M Z 2 4 2 if P/CHHPD A. Mass INVENTOR ATTORNEY Dec. 8, 1959 R. A. NEISS SEAL TESTER FOR PRESSURIZED CONTAINERS 2 Sheets-Sheet 2 Filed Aug. 27, 1957 \NVENTOR P/omlep A. Mass ATTORNEY 2,915,895 SEAL TESTER FOR PRESSUREZED CONTAINERS Richard A. Neiss, Bronx N.Y. Application August 27, 1957, Serial No. 680,531 9 Claims. (Cl. 7340) This invention is an apparatus for testing aerosol and other pressurized containers to determine if the cover or valve mounting cups of such containers have a tight impervious seal with the container.

It is the practice in packaging pressurized materials, such as aerosols, to attach the cover or valve cup or cap by crimping the same within the mouth of the container which generally has a rolled periphery. A gasket composition is ordinarily positioned between the cap and the edge of the mouth of the container and the cap is crimped below its upper edge to underlie the bead of the can and force the cap tightly in the direction of the can to form a hermetic seal. The crimping operation is usually performed by means of the crimping jaws of a sealing machine. Unless these crimping jaws are properly adjusted or, for other reasons well known to the art, the crimping operation is not properly carried out, leakage results.

The apparatus of the present invention provides a convenient and positive test to determine if the container is properly sealed and, among other things, facilitates the adjustment of the crimping machine employed so that it will produce a leak-proof container. Furthermore, it is essential in order to obtain a proper hermetic seal, that the cap and the container have compatible relation with respect to size and proportions. By the use of my apparatus, this fact can be quickly determined.

Various expedients have been resorted to for the testing of crimped seals on aerosol containers. The most common apparatus utilized for this purpose is one which tests the closure through the application of relative rotary torsional stresses between the cap and the container body. The amount of torsion which will resist movement between the cap and body is looked upon as the quantum of the test. If the cap turns easily or under slight torsion, the seal is considered insufiicient. If it stands greater torsion within a predetermined range the seal is considered satisfactory. Slippage occurring above this range indicates deformation of the can bead. However, in tests of this kind there is the ever present possibility that torsion exerted in the manner described will deform or rupture the gasket between the parts and cause subsequent leakage. Other attempts have been made to provide satisfactory apparatus for making tests of the character described, but none of them proved entirely satisfactory. For example, there is another standard method of testing which consists in submerging the entire container in a water bath heated to a predetermined temperature. This temperature is suflicient to heat the propellant gas in the container and thereby cause the pressure therein to rise and, presumably, cause leakage at faulty sealing points. However, this test is not always reliable because if the crimp in the cup is too low, a loose valve cap may be forced upwardly against the under side of the can bead with sufficient force to form a tight seal so that tendency to leak will not be disclosed. However, when the container cools to room temperature, the pressure of the propellant will be reduced and the Patented Dec. 8, 1959 cup will tend to drop sufficiently to permit leakage to occur.

The object of the present invention is to provide a test apparatus for the purposes stated which will be absolutely reliable, simple to operate and uniform in its operation throughout all tests. I

A further object of the invention is to'provide a nonestructive method of testing. I

The present invention operates on what I term a fprY principle, according to which the container is held stationary while a predetermined uniform force is applied against the under side of the cap, tending to lift it from the seal. If any leakage is indicated, the joint between the respective parts is not dependable and will cause subsequent seepage on storage. If the joint is tight and will not pry, even to the slightest degree, the seal is reliable and the crimp has been properly formed.

In its preferred practical form, my apparatus embodies means for supporting the can in predetermined upright position, while additional means, preferably in the form of a lever is arranged so that its work arm is engaged at the under edge of the cap. A weight of predetermined mass is thereupon imposed upon the power arm of the lever to effect the prying action to which I have referred. Appropriate means, such as a manual arm is provided to elevate the weight while the container is brought into test position and the lever arranged to engage with the lower edge of the cap. When the manually operable arm is released the weight is imposed upon the lever which performs the prying function referred to and effects the test. If the seal is unsatisfactory, the result of the prying operation may be noted, generally audibly by the issue of pressure at the point of application of the lever, although a suitable compound, such as liquid soap, may be applied about the joint prior to the test, so that the escape of pressure from the container may be visually noted by resulting bubbling. The indication of leakage may also be obtained through the use of the so-called Freon sniffer of the General Electric Company, which is well known to the trade.

' In testing the seal according to the apparatus of this invention, the test may be limited to one point in the circumference of the cap or it may be repeated at various points about such circumference if desired.

Features of the invention, other than those adverted to, will be apparent from the hereinafter detailed description and appended claims, when read in conjunction with the accompanying drawings.

The accompanying drawings illustrate one practical embodiment of the invention, but the construction therein shown is to be understood as illustrative, only, and not as defining the limits of the invention.

Fig. 1 is a central transverse section through apparatus embodying this invention, showing certain parts in elevation. This view shows the parts in testing positions.

Fig. 2 is a plan view of the upper portion of the apparatus of Fig. 1.

Fig. 3 is a fragmental section on the line 3-3 of Fig. l, with the parts in non-testing positions.

Fig. 4 is a fragmental perspective view of the bracket on which the container is supported during testing operatrons.

Fig. 5 is a section on the line 55 of Fig. 4.

In the drawings, 1 designates an appropriate base in which is mounted an upstanding hollow cylindrical column or standard 2, the upper end of which may be conveniently closed by a plug 3, detachably secured in position by a set screw 4. Integral with the upper portion of the column is a laterally extending bracket 5 which overlies the base 1. The outer end portion of this bracket is bifurcated and rabbeted to receive a pair ofidentical collar inserts 6 held in place by screws 7. The ini more easily fabricated.

. through the open side thereof, as indicated by the arrow a, Fig. 1. The opening 8 hasa thin edge adapted to embrace the neck of the container below the overhanging margin of the valve supporting cup 0, as shown best in Fig. 5.

The under margin about the opening 8 is provided with shoulders 9 adapted to rest upon the breast of the container, while the upper margin 10 about the opening is adapted to form a seat for the radially projecting marginal portion of thecup c, so that the container may be hung on said inserts, as indicated in Figs. 1 and 5. As will be noted in Figs. 4 and 5, the under side of the inserts are cut away or relieved as at 11, beyond the shoulders 9 to permit containers of brought into proper cooperative relation with the open different sizes to be ing 8.

The bracket 5 is provided in its upper portion with a slot 12 which extends radially from the interior of the column 2 to the opening 8. In this slot is positioned a lever 13, mounted on a fulcrum 14. The fulcrum is in the form of a pin seated in alined slots 15 in the inserts 6 and held in place by screws 16. V

The power arm of the lever 13 'is pivotally connected to a rod 17, anchored in the upper end of a weight 18 mounted within the hollow column 2 for vertical movement. This weight may be raised and lowered through the manual operation of an arm 19 secured to an eccentric 20, pivoted off center on a pin 21.

The work arm of the lever terminates in a finger 22, so shaped that, when the weight is in elevatedposition, this finger may enter between the breast of the container and the overhanging marginal portion of the valve carrying cup 0.

My test apparatus is used in the following manner: The arm 19 is manually raised by the operator. from the normal position shown in Fig. 3 to that of Fig. 1, to elevate the weight 18 with accompanying pivotal movement of the lever 13, so that the finger 22 of said lever is positioned substantially in the plane of the container receiving opening 8. The container to be tested in then introduced into said opening asshown in Fig. 1. .When properly positioned therein, it will be supported by and hung by the margin of the cup 0 which will rest upon the 4 tached vertical rod may be used to operate lever 19 from above water level.

-In practice the weight 18 is made of such mass that the prying operation described will effectually indicate whether or not the seal is satisfactory. It is important that such weight be of sufficient mass to indicate these facts, but the mass should not be so great as to unduly strain the container and cup assembly. In all cases, the prying action of the lever should exert more force upon the cup than that to which the cup will be subjected to by pressure within the container'C.

In some cases a single testing operation, such as described, may be carried out at only one point in the circumference of the cup, but, if desired, it may be repeated at different points about the circumference of the cup, to test for defects in sealing gasket lining or variation of crimp. Experience has shown that through the use of this invention, satisfactory tests of the seal may be obtained and that pressurized packages which pass this test are and will remain hermetically sealed against leakage at the joint between the container'body and the cup.

As hereinbefore stated, valve carrying cups are commonly crimped in the top opening of the container body in order to producev the assembly and effect a hermetic seal. In order to accomplish these results, it is essential that the crimping jaws ofthe sealing machine be properly adjusted. Such adjustment is diificult in theabsence of proper tests during the set up of a sealing machine. Through the use of the present invention the operation of crimping jaws may be immediately ascertained in a positive manner by making a test after each adjustment of the jaws and consequently such adjustment may be quickly and accurately made, with the result that an 'adjusting operation, which has heretofore been time consuming and uncertain, may, through the use of the present invention, be expeditiously and properly performed.

seat 10, with the finger 22 projecting beneath the overhanging marginal portion of said cup. After it is so positioned, the arm 19 is manually lowered to permit the weight 18 to be imposed upon the power arm of the lever 13. The weight will then act, through the work arm of the lever, against the under side of the overhanging 'margin of the cup 0 with an upward prying force, tending to lift the cup from the container which is precluded from upward movement by engagement of the breast of the container with the shoulders 9. If the cup has a proper seal with the body of the container, the attachment of the cup to the container body will firmly resist this prying action. If the attachment is faulty, such action will permit the escapeof pressure through thedefective seal and the presence of the resulting leakage will produce a hissing sound, audibly discernible by .theoperator. In lieuof the hissing telltale of leakage, a soap orsome other suitable solution may be applied about the seal before the test so that the presence of leakage will be indicated by the formation of bubbles. ()r, optionally, a so-called Freon sniifer may be employed in ried out under water (submerged),

suchas the standard method of hot water. bath testing.

In which case a t- When such a sealing machine has been properly adjusted with the help of my tester, the containers thereafter sealed by that machine will be hermetically sealed. The individual testing of such containers is therefore unnecessary but it is recommended that'tests be made from time to time to check wear on the machine .parts as well as containers and cups of different consignments to make sure of their compatability of size.

In the foregoing detailed description, I have set forth the apparatus of this invention in its preferred practical form. However, it will be understood that the mechanical design of the operating parts is secondary to the fundamental operational elements of the structure. 'For this reason, it will be understood that the present invention is not limited to the particular construction shown, but that it is fully commensurate with the appended claims.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. A seal tester for pressurized containers wherein an opening in the container body is sealed bya valve carrying cup having a marginal projecting pontion, comprising: a testing frame for supporting the body of the container in a predetermined position, a lever fulcrumed on the testing frame the work arm of which lever is adapted to project between the marginal portion of (the cup and the container body, and means acting upon the power arm of said lever to cause the work arm thereof to exert a prying action on the cup to test the effectiveness of the seal.

2. A seal testeraccording to claim- 1, wherein the means acting upon the power arm of the lever is a weight.

3. A seal tester according to claim 2, comprising man ually operable means for lifting the weight during the positioning of the assembled container andcup in cooperative relation with the work arm of the lever.

4. A seal tester for pressurized containers having a top opening sealed by a valve carrying cup with anoverhanging marginal portion, comprising: a testing frame for supporting a sealed container in predetermined upright position, a lever fulcrumed on the testing frame the work arm of which lever projects beneath the overhanging portion of the cup, and a weight suspended on the power arm of said lever and adapted to exert a lifting force on the cup to test the sufiiciency of the seal.

5. A seal tester according to claim 4, comprising manually operable means to lift the weight and place the work arm of the lever in position to project beneath the margin of the cup while the container is being positioned in cooperative relation with the means for supporting it.

6. A seal tester for pressurized containers having a container body an opening of which is sealed by a valve carrying cup, comprising: a support having a base and an upright standard on which is rigidly supported a bracket having an opening the margin of which is adapted to embrace the container body beneath the margin of the cup, a lever pivoted on said bracket with its work arm adapted to project beneath and engage with the margin of the cup and its power arm secured Ito a weight vertically movable in the standard.

7. A seal tester according to claim 6, comprising manually operable means for lifting the weight to permit the work arm of the lever to be so engaged with said cup.

8. A seal tester according \to claim 6, wherein the under margin of the bracket adjacent the opening constitutes a shoulder to engage with the breast of the container while the upper surface of the bracket marginally of the opening serves as a seat for the cup.

9. A seal tester according to claim 8, wherein the opening and its upper and lower marginal portions are formed on inserts secured to the bracket.

References Cited in the file of this patent 

